﻿using System;

using Org.BouncyCastle.Asn1;
using Org.BouncyCastle.Asn1.Kisa;
using Org.BouncyCastle.Asn1.Misc;
using Org.BouncyCastle.Asn1.Nist;
using Org.BouncyCastle.Asn1.Ntt;
using Org.BouncyCastle.Asn1.Oiw;
using Org.BouncyCastle.Asn1.Pkcs;
using Org.BouncyCastle.Asn1.X509;
using Org.BouncyCastle.Security;

namespace Org.BouncyCastle.Crypto.Utilities
{
    public class AlgorithmIdentifierFactory
    {
        public static readonly DerObjectIdentifier IDEA_CBC = MiscObjectIdentifiers.as_sys_sec_alg_ideaCBC;
        public static readonly DerObjectIdentifier CAST5_CBC = MiscObjectIdentifiers.cast5CBC;

        private static readonly short[] rc2Table = {
            0xbd, 0x56, 0xea, 0xf2, 0xa2, 0xf1, 0xac, 0x2a, 0xb0, 0x93, 0xd1, 0x9c, 0x1b, 0x33, 0xfd, 0xd0,
            0x30, 0x04, 0xb6, 0xdc, 0x7d, 0xdf, 0x32, 0x4b, 0xf7, 0xcb, 0x45, 0x9b, 0x31, 0xbb, 0x21, 0x5a,
            0x41, 0x9f, 0xe1, 0xd9, 0x4a, 0x4d, 0x9e, 0xda, 0xa0, 0x68, 0x2c, 0xc3, 0x27, 0x5f, 0x80, 0x36,
            0x3e, 0xee, 0xfb, 0x95, 0x1a, 0xfe, 0xce, 0xa8, 0x34, 0xa9, 0x13, 0xf0, 0xa6, 0x3f, 0xd8, 0x0c,
            0x78, 0x24, 0xaf, 0x23, 0x52, 0xc1, 0x67, 0x17, 0xf5, 0x66, 0x90, 0xe7, 0xe8, 0x07, 0xb8, 0x60,
            0x48, 0xe6, 0x1e, 0x53, 0xf3, 0x92, 0xa4, 0x72, 0x8c, 0x08, 0x15, 0x6e, 0x86, 0x00, 0x84, 0xfa,
            0xf4, 0x7f, 0x8a, 0x42, 0x19, 0xf6, 0xdb, 0xcd, 0x14, 0x8d, 0x50, 0x12, 0xba, 0x3c, 0x06, 0x4e,
            0xec, 0xb3, 0x35, 0x11, 0xa1, 0x88, 0x8e, 0x2b, 0x94, 0x99, 0xb7, 0x71, 0x74, 0xd3, 0xe4, 0xbf,
            0x3a, 0xde, 0x96, 0x0e, 0xbc, 0x0a, 0xed, 0x77, 0xfc, 0x37, 0x6b, 0x03, 0x79, 0x89, 0x62, 0xc6,
            0xd7, 0xc0, 0xd2, 0x7c, 0x6a, 0x8b, 0x22, 0xa3, 0x5b, 0x05, 0x5d, 0x02, 0x75, 0xd5, 0x61, 0xe3,
            0x18, 0x8f, 0x55, 0x51, 0xad, 0x1f, 0x0b, 0x5e, 0x85, 0xe5, 0xc2, 0x57, 0x63, 0xca, 0x3d, 0x6c,
            0xb4, 0xc5, 0xcc, 0x70, 0xb2, 0x91, 0x59, 0x0d, 0x47, 0x20, 0xc8, 0x4f, 0x58, 0xe0, 0x01, 0xe2,
            0x16, 0x38, 0xc4, 0x6f, 0x3b, 0x0f, 0x65, 0x46, 0xbe, 0x7e, 0x2d, 0x7b, 0x82, 0xf9, 0x40, 0xb5,
            0x1d, 0x73, 0xf8, 0xeb, 0x26, 0xc7, 0x87, 0x97, 0x25, 0x54, 0xb1, 0x28, 0xaa, 0x98, 0x9d, 0xa5,
            0x64, 0x6d, 0x7a, 0xd4, 0x10, 0x81, 0x44, 0xef, 0x49, 0xd6, 0xae, 0x2e, 0xdd, 0x76, 0x5c, 0x2f,
            0xa7, 0x1c, 0xc9, 0x09, 0x69, 0x9a, 0x83, 0xcf, 0x29, 0x39, 0xb9, 0xe9, 0x4c, 0xff, 0x43, 0xab
        };


        /**
    * Create an AlgorithmIdentifier for the passed in encryption algorithm.
    *
    * @param encryptionOID OID for the encryption algorithm
    * @param keySize key size in bits (-1 if unknown)
    * @param random SecureRandom to use for parameter generation.
    * @return a full AlgorithmIdentifier including parameters
    * @throws IllegalArgumentException if encryptionOID cannot be matched
    */
        public static AlgorithmIdentifier GenerateEncryptionAlgID(DerObjectIdentifier encryptionOID, int keySize, SecureRandom random)

        {
            if (encryptionOID.Equals(NistObjectIdentifiers.IdAes128Cbc)
                    || encryptionOID.Equals(NistObjectIdentifiers.IdAes192Cbc)
                    || encryptionOID.Equals(NistObjectIdentifiers.IdAes256Cbc)
                    || encryptionOID.Equals(NttObjectIdentifiers.IdCamellia128Cbc)
                    || encryptionOID.Equals(NttObjectIdentifiers.IdCamellia192Cbc)
                    || encryptionOID.Equals(NttObjectIdentifiers.IdCamellia256Cbc)
                    || encryptionOID.Equals(KisaObjectIdentifiers.IdSeedCbc))
            {
                byte[] iv = new byte[16];

                random.NextBytes(iv);

                return new AlgorithmIdentifier(encryptionOID, new DerOctetString(iv));
            }
            else if (encryptionOID.Equals(PkcsObjectIdentifiers.DesEde3Cbc)
                    || encryptionOID.Equals(IDEA_CBC)
                    || encryptionOID.Equals(OiwObjectIdentifiers.DesCbc))
            {
                byte[] iv = new byte[8];

                random.NextBytes(iv);

                return new AlgorithmIdentifier(encryptionOID, new DerOctetString(iv));
            }
            else if (encryptionOID.Equals(CAST5_CBC))
            {
                byte[] iv = new byte[8];

                random.NextBytes(iv);

                Cast5CbcParameters cbcParams = new Cast5CbcParameters(iv, keySize);

                return new AlgorithmIdentifier(encryptionOID, cbcParams);
            }
            else if (encryptionOID.Equals(PkcsObjectIdentifiers.rc4))
            {
                return new AlgorithmIdentifier(encryptionOID, DerNull.Instance);
            }
            else if (encryptionOID.Equals(PkcsObjectIdentifiers.RC2Cbc))
            {
                byte[] iv = new byte[8];

                random.NextBytes(iv);

                RC2CbcParameter cbcParams = new RC2CbcParameter(rc2Table[128], iv);

                return new AlgorithmIdentifier(encryptionOID, cbcParams);
            }
            else
            {
                throw new InvalidOperationException("unable to match algorithm");
            }
        }
    }
}